PV: Storage and Controllable Consumption – The Future of the NI Grid

In the last ten years NI has experienced a rapid expansion of relatively small, independently owned, clean renewable energy (RE) generators. These range from wind farms, individual wind turbines, hydro, biogas powered combined heat and power (CHP) plants, to large and small scale solar photovoltaics (PV). This growth has been a resounding success for NI; providing an abundance of clean renewable electricity, bolstering NI’s energy independence and suppressing the electricity costs for all consumers in NI. However, this has caused challenges for NI’s grid.

The Challenges
Northern Ireland’s grid must be able to supply electricity to consumers in concentrated centres (such as cities/towns), but also to many rural and isolated electricity consumers (rural industries or manufacturers). Many of these isolated electricity consumers are at the furthest end of electricity lines, so their electricity supply network may be somewhat weak. This makes the provision of a secure and reliable supply of electricity to all consumers in NI a bit of a challenge. I.e., to ensure adequate supply to many different consumers with vastly different consumption profiles, situated in various parts of the country, requires robust transmission and distribution lines a combined with very intimate and rapid control of generators.

The introduction of RE generators has created an additional challenge in managing and delivering electricity supply. This is because RE generators are generally not controllable and therefore provide their electricity directly onto the grid at the time and place of generation, decreasing demand in that area. So, for example, on sunny days, electricity from solar PV flows on to the grid and conventional fossil fuel generators must be made to turn down their supply correspondingly. However, conventional fossil fuel generators must also be kept on standby, ready to generate when renewable electricity generation falls. This instantaneous control of supply to match varying demand and to react to the intermittent generation from renewables, is challenging to manage. But this type of ‘balancing’ of the grid is essential to maintain NI’s electricity supply.

Solution
The solution to this balancing problem – complicated by the installation of RE technologies - could ultimately lie in the hands of the RE generators.

If the many thousand small scale PV generators in NI also installed electricity storage in the form of batteries, they could store and control the release of their excess electricity generation. This stored electricity, could be released onto the grid instantaneously when the local demand is high and/or supply is low. Or they could take energy off the grid when the supply outstrips demand. Essentially these batteries could ‘fill the gap’ between demand and supply, instantaneously and at a local level.

This solution would offer dual benefits to the owner of the PV and batteries:
(1) The owners can minimise their electric bill cost, by lowering their consumption from the grid.
(2) They can get paid for what they export to the grid and for the ‘balancing’ services they provide to the grid.

So, what is holding us back?
The cost of batteries and monitoring and control systems? These are dropping rapidly, to the point that they can be paid back solely from electricity bill savings within a matter of years.

The approval of the grid operator? NIEN have green-lighted a limited trial of controllable battery storage systems in NI and have been happy with the results so far. Click here if you are interested in learning about or joining this trail.

The regulatory environment? The Utility Regulator of Northern Ireland has been responsible for the implementation of the DS3 programme (Delivering a Secure, Sustainable Electricity System). This programme provides the scope for RE generators with storage to be remunerated for providing grid balancing services. However, the exact mechanism and value of these services is still under development. Therefore, while it is still early days for PV (or other renewables) to implement controllable storage in NI, the concept is a well-established one and the stage is getting set for NI based renewable generators to grasp the opportunities that this solution can offer. The future of the NI grid must be smart.

If you would like to join a limited NIEN approved trail for battery storage on your PV system, please use this link to register your interest or give Action Renewables a call on 028 9072 7760 and we would be happy to talk to you about this opportunity.

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